The invention relates to a method for generating different signals depending on whether a vehicle drives in a curve or on a straightaway and a method for determining the transverse acceleration while driving in curve.
From navigation systems it is known to determine the approximate driving direction of the vehicle from the difference .DELTA.v of the sensor signals from the non-driven wheels of a vehicle.
In anti brake lock control systems or anti slip control systems, it is also known to use steering angle sensors and/or transverse accelerometer and supply the output signals thereof as parameters to the control. The use of only the difference .DELTA.V is not sufficient in this case since interferences can adversely affect these differences and since different circumferential distances (wheel diameters) can also lead to incorrect statements.
According to the invention, the difference .DELTA.v between the speeds of the left and right non-driven wheels is filtered so that the filtered difference .DELTA.v.sub.F follows those changes having an increase greater than .+-. a with a delay, where a is about 0.2 g.
.DELTA.v.sub.F and the mean valve v.sub.M of the speed signals serve to form correction signals K.sub.i according to the relation: ##EQU1## where .DELTA.v.sub.g is a function which is stored and dependent upon the vehicle speed, and K.sub.2 is formed only when .vertline..DELTA.v.sub.F .vertline.&gt;.DELTA.v.sub.G. A mean value K.sub.i is formed from the successively determined correction signals K.sub.i, and a corrected difference .DELTA.v.sub.k is formed from .DELTA.v.sub.F according to EQU .DELTA.v.sub.K =.DELTA.v.sub.F -K.sub.i v.sub.M
wherein the correction K.sub.1 is used when K.sub.1 is formed once during a ride. A signal which indicates driving in a curve is generated if .DELTA.v.sub.K exceeds a small speed value.